Pop-up irrigation sprinklers are commonly used in irrigation systems where it is necessary or desirable to install the sprinklers in the ground so that they do not project appreciably above ground level when not in use. In a typical pop-up sprinkler, a sprinkler mechanism is telescopically housed within a generally cylindrical upright sprinkler case having an open upper end. In a normal inoperative position, a pop-up portion of the sprinkler mechanism, including a spray head, is normally spring-retracted substantially into the sprinkler case so that it does not extend or project a significant distance above the open upper end of the case. However, when water under pressure is supplied to the sprinkler case, the spray head is displaced upwardly through the open end of the case to an elevated spraying position above the sprinkler case to facilitate the delivery of an outwardly projecting stream of water to a surrounding area.
In some pop-up sprinklers, the sprinkler mechanism includes a rotary drive system to rotate the elevated spray head through continuous full circle revolutions or, alternately, back and forth within a predetermined partial arcuate path to sweep the projected water stream over a selected target terrain area. In this regard, the sprinkler mechanism has been designed to receive a removable nozzle insert selected from a set of different inserts. Each insert is designed to cause the sprinkler mechanism to produce a projecting water stream of different characteristics, such as flow rate, trajectory, stream width, area coverage etc., in accordance with the particular irrigation requirements for each pop-up sprinkler in the system. The interchangeable nozzle inserts provide a convenient and efficient system to custom-tailor the projecting water stream. Examples of rotary-drive, pop-up sprinklers of this general type include those disclosed in U.S. Pat. Nos. 4,625,914 and 4,787,558.
Nozzle inserts have been produced from lightweight, molded plastic to have a size and shape for quick and easy installation and removal on the spray head. In one form, nozzle inserts have been produced in a unitized set formed integrally with a common mold runner. The mold runner provides a convenient carrier for packaging, storing and transporting the nozzle set. An example of a carrier with such design is disclosed in U.S. Pat. No. Des. 415,415.
As mentioned above, each insert of the nozzle set can define different spray characteristics for the projecting water stream. One of the nozzle inserts can be detached quickly and easily from the carrier and installed into a sprinkler spray head to custom-select the spray characteristics for the water stream. Thereafter, periodic changing of the nozzle insert can be accomplished to tailor the specific water spray characteristics according to the maturation and growth of the surrounding vegetation or, alternately, according to changes in the vegetation type.
However, experience has revealed that a shortcoming of current carriers is that the inserts tend to become unintentionally detached. For example, in the course of packaging the nozzle sets or carrying nozzle sets in the field, individual nozzle inserts frequently are susceptible to accidental detachment from their associated carrier and can be lost. Thus, it is desired to have an improved nozzle insert set and corresponding carrier, including one that addresses the shortcoming associated with unintentional detachment of the inserts.